This application is for a new institutional NRSA to support the training of initially two and subsequently five M.D. and Ph.D. Postdoctoral Fellows. Although a new program several of the training faculty have been highly interactive in training such individuals in the past and faculty as a whole has been highly successful in training individuals over the last ten years who now hold academic or research appointments. For example trainees who have left the program of training within the last five years show significant continuing involvement in research (approximately 70% have greater than 50% effort devoted to research). The broad objective of this program is to provide multi-disciplinary training in problem oriented research on the pathophysiology of mucosal disease with special reference to polarized epithelial and alimentary tract disorders. The training faculty consists of twenty investigators with independent, funded research programs related to this area of study. The faculty provides expertise in modern molecular, immunologic and cell biologic approaches for studying pathophysiology of disease. There exists particular emphasis on epithelial biology and immunology as it relates to epithelial biology and immunology as it relates to epithelial biology at sites such as the alimentary tract. The structure of the training program is designed to promote interactions among participating faculty and to provide trainees access to all of the laboratories and their considerable resources. Trainees are selected from graduate and clinical programs nationwide with an emphasis on identifying under-represented minorities. The major component of the training program is independent research carried out by trainees in their laboratories of choice. The training experience is further enhanced by attendance at research conferences, journal clubs and formal seminars as well as attendance in coursework largely provided by the faculty of this training program (i.e. the faculty of the training program are highly interactive in the graduate education program at Emory University School of Medicine).